The overall objective of this K-Award is to facilitate my development as an independent clinical researcher studying inflammatory markers and daytime sleeping among older people at risk for functional decline. This research area is directly relevant to the NIA's mission to address age-related diseases and problems and to provide training in aging related research. My short-term goals are to develop new skills in immunology to compliment my prior training in behavioral medicine and health psychology and to conduct research on cytokines, sleep and rehabilitation outcomes. The career development activities proposed within this K- Award were selected to provide me with new skills through carefully planned training activities, including formal coursework, ongoing lecture series, scientific meetings, and mentorship from senior scientists to expand my knowledge about immunology (particularly proinflammatory cytokines), changes in immune functioning with age, and the interactions between sleep and the immune system. My primary long-term goal is to use a comprehensive biological model to understand interactions between the immune system and sleep patterns and examine the potential for improved sleep patterns to improve health outcomes for older people. The proposed research focuses on a specific group of vulnerable older people: those recovering from acute illness or injury in the post-acute rehabilitation setting, where we have previously found that more daytime sleeping during rehabilitation predicts poorer functional recovery. The proposed project developed from this prior research work and my interest in biological markers. The specific aims of the proposed project are to: 1) examine the relationship between daytime sleepiness during post-acute rehabilitation and levels of proinflammatory cytokines;2) examine the relationship between levels of proinflammatory cytokines during rehabilitation and 1-year functional outcomes;and 3) examine the relationship between daytime sleepiness during post-acute rehabilitation and death or nursing home placement within 1 year, among older people receiving post-acute rehabilitation. The study will share resources with my primary mentor's (Dr. Cathy Alessi) ongoing research projects in the post-acute rehabilitation setting. Participants (n=222) will complete an assessment battery including objective and subjective assessments of sleep and function, and will provide one blood sample, which will be assayed for proinflammatory cytokines (IL-6 and ICAM-1) during post-acute rehabilitation. Participants will be followed for 1 year to assess functional and health outcomes. Understanding the relationship between daytime sleeping and the immune system among older people at risk for death, nursing home placement or functional decline has the potential to improve functioning and health. This may have trememdous public health impact as the number of older people with medical problems continues to grow, and targeting resources to improve outcomes becomes increasingly critical.